1. Field of the Invention
The present invention relates to determining an internal resistance for an energy source, such as but not limited to a lead-acid battery used in a vehicle to provide direct current (DC) potential.
2. Background Art
Battery internal resistance is a basic value that can be used together with measured battery voltage, current and temperature by various vehicle systems and algorithms to evaluate the status of the battery and provide battery variables like real capacity, status of health, remaining minutes to total discharge, etc. Internal resistance, thus, enables battery status evaluation with even some forecast, which can be helpful in insuring sufficient supplies of electrical energy (battery capability to supply such) for vehicle critical functions like electric braking, start-stop functions and the like.